package modellayer;

import java.io.Serializable;

/**
 * This interface is for subclasses that implement either different
 * kinds of discounts calculated in different ways or containers
 * holding these.
 *  
 * @author (ucn-1semprojekt-dm78-gruppe1)
 *
 */
public interface DiscountSubTotal extends Serializable
{
	
	/**
	 * @param normPrice the price to be discounted (cut off)
	 * @param amount the amount or pieces to be bought. Can be used
	 * to multiply the price if used in a container subclass.
	 * @return the discounted price 
	 */
	public double subTotal(double normPrice, int amount);
}
